Answer:
This is the first answer,
winter solstice
The winter solstice occurs during the hemisphere's winter. In the Northern Hemisphere, this is the December solstice (usually December 21 or 22) and in the Southern Hemisphere, this is the June solstice (usually June 20 or 21).
and this is the second one,
the tilt of the Earth on its axis
Seasons change because of the tilt of the Earth and the planet's movement around the Sun. Did you know? It takes about 365.25 days for the Earth to orbit the Sun. We have leap years to make up for the extra ¼ day!
Answer:
These are the elements or compounds that enter into a chemical reaction: Reactants
These are the substance(s) formed in a chemical reaction: Products
These are the reactants in the chemical equation C6H1206 +602 --> 6CO2 + 6H20: C6H1206 and 602
These are the reactants in the chemical equation 6 CO2 + 6H2O --> C6H1206 + 6 02: 6 CO2 + 6H2O
These are the reactants in the chemical equation 2 H2 + 02 --> 2 H2O: 2H2 and O2
These are the reactants in the chemical equation 2 H2O --> 2 H2 + O2: 2H2O
The formula is:
frequency * h (Planck's constant) = Energy
So, to find frequency you need just divide energy by the constant:
frequency = (8 * 10^-15 J) / (6.63 * 10^-34 J*s) = 1.2 * 10^19 1/s or 1.2 * 10^19 Hz
Visible and infrared light do not cause sunburn and they are not known to directly be a skin cancer risk.